Technical Field
The present invention relates generally to a method of automatically analyzing (e.g., measuring) an uplink path of a Distributed Antenna System (DAS). More particularly, the invention relates to a system and method for automatically measuring an uplink noise level of a DAS, measuring the noise level of each Remote Unit (RU) link of a plurality of RU links, at the final end of an uplink path, and then using the noise level to check the status of the uplink path of the DAS.
Description of Related Art
In general, a DAS includes a Base Station Transceiver Subsystem (BTS), a Head End (HE), and a plurality of Remote Units (RUs). The DAS may be located in (or placed in) shadow areas that radio waves generally cannot reach, such as a large-sized building, a campus, a stadium, a hospital and/or a tunnel. Signals of the BTS may be amplified so that the signals can reach the shadow areas.
The DAS may also function to amplify signals requested by terminals located in (or placed in) the shadow areas and then transmit the amplified signals in a direction opposite to the above-described relay direction. For example, a signal transmitted by a user terminal may be transmitted over an uplink path from the user terminal to a BTS/Bi-Directional Amplifier (BTS/BDA). The signal transmitted by the user terminal is first input to an RU located in (or placed in) a corresponding service area. The input signal is amplified with an appropriate gain via the RU, converted into an optical signal, and then transmitted to an HE over an optical cable. The HE converts the optical signal into a Radio Frequency (RF) signal, amplifies the converted signal with an appropriate gain, and sends the amplified signal to the BTS/BDA.
However, after being installed and while operating, a conventional DAS may not be able to check the status of an uplink path. For example, the DAS may not be able to check for conditions such as a deteriorated gain status of an uplink path, self-oscillations attributable to the influence of an antenna of a specific RU uplink, or an inflow of external spurious signals. In such cases, it may only be possible to take measurements at the point when a terminal user senses a deterioration of quality and makes a complaint.
Furthermore, a conventional DAS may be problematic in that, in the case where a plurality of RUs is installed, two or more persons may be needed to check the status of an uplink path. That is, one person may have to check the status of an uplink path at a HE using a measuring device and another person may have to visit each of the RUs, detach an antenna from the RU, perform electrical termination processing (e.g., 50 ohm termination processing), and then check the status of each RU while communicating with the person located at (or placed at) the HE. Accordingly, there may be problems in that measurements relating to the status of an RU cannot be taken promptly and the status of an RU cannot be checked in an area where the RU is inaccessible to people.
It is therefore desirable to provide a system and method for automatically analyzing (e.g., measuring) an uplink path of a DAS.